DARMSTADT, Germany (AP) — European Space Agency says it has succeeded in landing a spacecraft on a comet for 1st time.

The Agency says the spacecraft it successfully landed on a comet may have bounced once, before coming to rest.

The head of the lander operation Wednesday said thrusters that were meant to push the lander down and harpoons that would have anchored it to the surface failed to work.

Stephan Ulamec told reporters in Darmstadt, Germany, that data received from the Philae lander indicates it lifted off from the comet, turned slightly and then landed again.

Ulamec says scientists are still trying to fully understand what happened but so far most of the instruments are working fine and sending back data as hoped.

The landing was the climax of the decade-long Rosetta mission to observe comet 67P/Churyumov-Gerasimenko.